Formal:
* Koj mus zoo: This is a very common and polite way to say "have a nice day," literally meaning "you go well."
* Koj mus zoo zoo: This is a more emphatic version of "Koj mus zoo," adding "zoo" for emphasis.
Informal:
* Mus zoo: This is a more casual way to say "have a nice day," similar to "have a good one."
* Sawv zoo: This means "go well," and can also be used as a casual way to say "have a nice day."
It's important to note that these are just a few examples, and there may be other ways to say "have a nice day" in Hmong depending on the specific dialect and context. It's always best to consult with a native speaker if you're unsure.